NOTE: Scale ranges from 0 to 500. The U.S. history data include students for whom accommodations were permitted. For a discussion of the U.S. history scale score definitions, see http://nces.ed.gov/nationsreportcard/ushistory/scale.asp. Race categories exclude persons of Hispanic ethnicity.

SOURCE: U.S. Department of Education, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 1994, 2001, and 2006 U.S. History Assessments and NAEP Data Explorer, retrieved January 22, 2008, from http://nces.ed.gov/nationsreportcard/nde/.